Gasping for breath after running up a steep San Francisco hill, Robby Benson began to faint. He grabbed for a parking meter to break his fall. Then he became violently sick to his stomach. It all happened on location during the filming of Die Laughing, in which he starred, co-wrote and was a producer. He was in his early 20s, a onetime teen idol now transitioning into bigger challenges with the promise of a long, successful career in Hollywood. He didn't want to tell the truth: doctors had found a heart murmur when he was a teenager and for years he'd suffered similar symptoms.